In the related art, a technique is known which determines, as abnormality, a case in which an estimated torque becomes excessive with respect to a required torque by comparing the required torque of a driver calculated on the basis of a drive manipulated variable (for example, an accelerator opening degree detection value and the like) by the driver with the estimated torque calculated on the basis of operating states (for example, a detection value of an intake air volume to an internal combustion engine and the like) of a drive source (see PTL 1).